The FM8515B Issue 2 optical power meter extends the low-end dynamic range of FM8515B to -70 decibels with reference to one milliwatt, with the upper end at +5 dBm. The original units were calibrated down to -60 dBm. Battery life has been extended to approximately 100 hours, and the units can now be calibrated in less than 30 minutes. The FM8515C Issue 2 high-power version has a dynamic range of -50 to +25 dBm and is suitable for applications in cable TV and in long-span telephone and data communications. Both units are three-wavelength optical power meters featuring reference store, automatic power off, and a low-battery indicator.